While Railpower was still dabbling with their hybrid "Green Goat" switchers, NRE rocked the switching locomotive world with its first Genset switcher, alternately known at first as a TES, or Truck Engine Switcher. The original unit was UPY 2005, and had a pair of 700-hp Cummins QSK19 engines on either side of a center-mounted cab. The original invoked a lot of comparisons to ALCo's diminutive C-415 switcher.

NRE, or National Railway Equipment, has a large used locomotive lease fleet, and also does extensive rebuild work. They have shops in thier home base of Dixmoor, IL, along with shops in Mt. Vernon and Silvis, IL and the former VMV shop in Paducah, KY. The similarity of the UPY 2005 to an early ALCo design is likely no coincidence, as NRE also owns the rights to ALCo's designs.

NRE offers four different genset models - a single engine 700hp model 1GS7B, the twin engine 1,400hp model 2GS14B, the three engine 2,100hp 4 axle 3GS21B, and the three engine 2,100hp six axle 3GS21C. A fifth variant, the six axle, four engine 3GS28C, has been announced, but as of Sept. 2009 none have been built. Also, a separate listing is provided here for the 3GS21B-DE unit, which is a 3GS21B that is equipped with extended range dynamic braking.